1. Field of the Invention
The present invention relates, in general, to image sensor modules used in a variety of electronic apparatuses and, more particularly, to a thin sensor module with a zooming function, in which the condensing lenses are movable to change their positions, thus accomplishing a zooming effect while precisely condensing light beams to produce clear images.
2. Description of the Prior Art
As well known to those skilled in the art, image sensor modules are installed in a variety of electronic apparatuses, such as video cameras, digital still cameras, PC cameras, mobile phones, PDAS, etc., for image capture. In recent years, in accordance with a variety of requirements of mobile phone consumers, manufacturers of mobile phones have actively studied enhancement of the functions of their mobile phones.
In an effort to enhance the functions of such mobile phones, digital cameras fabricated using image sensor modules have been added to mobile phones. Such a mobile phone with a digital camera transmits an image to the phone of a phoning companion, and displays an image, transmitted from the companion""s phone, on its LCD, thus allowing users to conveniently transmit and receive images through their mobile phones.
The conventional mobile phones which can be used with such digital cameras are classified into several types, that is, bar-type phones with a variety of numerical and function buttons provided on the phone body to be directly exposed to the outside, flip-type phones with a hinged cover covering the buttons, and folding-type phones with a folding main body. In accordance with the recent trend toward smallness and compactness of mobile phones, the folding-type phones have become more widely used than the other type phones.
FIG. 1 shows the construction of a folding-type mobile phone with a conventional detachable digital camera. As shown in the drawing, the detachable digital camera 2 can be attached to the ear jack terminal 1d formed at the main body 1a of the mobile phone 1 using a dummy plug 3. In order to attach the detachable digital camera 2 to the body 1a of the mobile phone 1 using the dummy plug 3, the digital camera 2 has an ear jack terminal 2b in the same manner as the ear jack terminal 1d formed at a sidewall of the phone""s body 1a. The dummy plug 3 has two plug terminals 3a and 3b at both ends of a central plug body 3c, and electrically couples the camera 2 to the phone 1 by the first and second plug terminals 3a and 3b respectively inserted into the two ear jack terminals 2b and 1d. In brief, temporary attachment of the digital camera 2 to the mobile phone 1 is accomplished by insertion of the two plug terminals 3a and 3b of the dummy plug 3 into the two ear jack terminals 2b and 1d. 
When the digital camera 2 is attached to the mobile phone 1 by means of the dummy plug 3 as described above, the camera 2 is rotatable around the axis of the plug 3, thus allowing a user to control the photographing direction of the camera 2 in accordance with the position and focused angle of an objective, such as a person or a scene, to be photographed. That is, when photographing an objective, such as a person or a scene, using the digital camera 2, the user controls the direction of the camera 2 while viewing the position and focused angle of the objective, displayed on the LCD 1c provided at the fold 1b of the phone 1.
FIG. 2 shows the internal construction of a conventional image sensor module installed in such a detachable digital camera 2, for image capture. As shown in the drawing, the sensor module comprises a housing 10 defining a cavity 11 therein.
A holder 20 is mounted to the first end of the housing 10, with a condensing lens 21 set in the holder 20 for precisely condensing an image.
An iris filter 30, used to regulate the amount of light, is set in the cavity 11 of the housing 10 while being fixed to the housing 10 by means of an epoxy resin 40. A ceramic circuit board 50 is fixedly mounted to the second end of the housing 10 by means of an epoxy resin 40.
Mounted on the top surface of the circuit board 50 at a position inside the housing 10 is an image sensor 51.
The image sensor 51 is mounted to the top surface of the circuit board 50 through a die-bonding process, and is electrically connected to a circuit of the board 50 through a wire-bonding process.
In the above description, the image sensor module is described as it is used in a digital camera for mobile phones. However, it should be understood that such sensor modules may be preferably used in a variety of cameras, including such digital cameras for mobile phones, to accomplish the recent trend toward thinness, compactness and lightness of the cameras.
When the digital cameras using the sensor modules of FIG. 2 are used with portable electronic apparatuses, such as mobile phones, the digital cameras are somewhat inconvenient to users while photographing an objective, as follows: that is, when it is desired to enlarge or reduce the size of a photographed image, a user manually and carefully moves the apparatus with the camera toward or away from the objective while viewing the focused images displayed on the LCD, so the camera is inconvenient to the user.
The above problem is caused by a structural default of the conventional sensor module in that the position of the condensing lens for condensing light beams to produce images is fixed in the barrel of the sensor module, so the sensor module cannot accomplish a zooming function.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an image sensor module with a zooming function, which is used in a variety of electronic apparatuses, and in which the condensing lenses are movable to change their positions, thus accomplishing a zooming effect while precisely condensing light beams to produce clear images.
In order to accomplish the above objects, the present invention provides an image sensor module with a zooming function, comprising: first and second barrels for respectively holding condensing lenses used for image capture; a housing having a guide channel at a sidewall thereof and movably and stably receiving the first extensions of the first and second barrels in the guide channel such that the first and second barrels are moved along a focusing axis of the condensing lenses and are stably held at selected positions; a motor for generating a rotating force; a motor gear formed on the output shaft of the motor; and a means for controlling the interval between the first and second barrels by converting a rotating action of the motor gear into a linear movement of the first and second barrels in a horizontal direction.
In an embodiment, the interval control means comprises: a rotary cam disc rotatably provided outside the housing, with two arc-shaped guide slots formed on the cam disc at opposite positions spaced apart from each other at an angular interval, the cam disc receiving the second extensions of the first and second barrels in the guide slots, respectively; and a rotary cam gear formed on the rotary cam disc, and engaging with the motor gear such that the rotary cam gear is rotated by the rotating force of the motor gear in a direction opposite to the rotating direction of the motor gear.
In another embodiment, the interval control means comprises: two cam gears positioned to be opposite each other and jointed to the second extensions of the first and second barrels, respectively, and also engaging with the motor gear such that the cam gears convert the rotating action of the motor gear into the linear movement of the first and second barrels in the horizontal direction.